In broadband networks in which a point-to-point connection is created between a central office (CO) and a subscriber or user, a crash typically only locally affects that particular subscriber. The problem can be better understood in the case of a Digital Subscriber Line (DSL) network 100 shown in FIG. 1a where a plurality of point-to point connections 102a . . . n are arranged to connect a central office (CO) 104 to a plurality of subscribers or users 106a . . . n using a twisted pair infrastructure. Of course, the DSL network may be arranged in a broadcast type arrangement. However, as shown in FIG. 1a there is a relative advantage to be observed in that a crash of the modem (not shown) corresponding to subscriber 106b is localized to that subscriber. In other words, should the modem of subscriber 106b malfunction or go offline unexpectedly or otherwise transmit spurious signals on the line, the only channel affected is the line or connection 102b. In addition, the subscriber may be able to resolve the situation without service support simply by manually resetting the DSL modem. The problem may also be resolved remotely by the network carrier or CO operator since the problem is localized to a specific and known connection.
While such point-to-point connections may be considered more robust in that they are more resistant to being effected by disturbances outside their connection, such systems typically are limited in bandwidth. Point-to-point communication networks also offer dedicated lines to different subscribers, thereby multiplying the number of lines required in such systems as compared with broadcast or shared connection arrangements. In addition, when the point-to-point modem malfunctions and is not resettable, typically service must be carried out for that particular unit or connection. Therefore, point-to-point connection may be considered to be resource intensive while providing a lower end of the bandwidth available from various network arrangements.
On the other hand, communication networks arranged in a broadcast arrangement or shared connection arrangement are capable of sharing resources such as communication connections or lines. Shared lines also allows for combining bandwidth on several lines, thereby allowing for increased bandwidth over point-to point arrangements. In a broadcast arrangement, typically a single CO broadcasts data or communication signals to a plurality of subscribers over a plurality of lines. In many instances the CO listens to the traffic collectively from several lines, which may be connected to a single point at the CO end. In such an arrangement, the communication system is greatly reduced in terms of resources. In addition, typically greater bandwidth is available or bandwidth balancing may be engaged to offer greater bandwidth in some instances.